In lighting control systems with distributed networked/intelligent lighting devices it is imperative that the unique network address of each device is correctly identified and associated with its relevant locations/areas of control to facilitate correct operational configuration of the system.
Current identification methods include, for example, removing a detachable, printed identification (ID) number and/or scan-able code sticker from the lighting device upon installation and fixing the printed ID to an installation drawing that depicts the location of the associated lighting device. The installation drawing is later referred to when commissioning/configuring the lighting system.
In another method, a barcode (or other scan-able medium) is removed and affixed to a drawing for later scanning (or scanned in-situ) and used to directly update information within a commissioning application (software or handheld tool).
In a further method, if the identification of installed, networked device has not been previously recorded, it is then possible to identify the networked device by pressing a “service pin” (a physical button on the device) while a commissioning app/tool is in a listening mode. The address of the device is then displayed or assigned to a pre-configured “dummy”/virtual device in the physical location.
Another method involves a wink function, wherein, to facilitate observational identification of luminaires particularly with networked Digital Addressable Lighting Interface (DALI®) addressed devices, which generally do not support the previous methods, the network is scanned for previously un-provisioned devices using a commissioning app/tool. The un-provisioned devices are then listed on a screen. A “wink” option button for each of the results is provided and when selected causes the related luminaire to flash on and off repeatedly. When witnessed by an engineer, the device address can then be correctly assigned.
An additional method is visual light communication (VLC) over Radio Frequency (RF) communication, which has the advantages of high bandwidth and immunity to interference from electromagnetic sources. VLC refers to an illumination source, which in addition to illumination can send information using the same light signal. VLC(s) are an emerging form of communications that use visual forms of light emitters to communicate data wirelessly. VLC uses a light source that is frequency-modulated and/or turned on and off rapidly when transmitting a communication. VLC systems employ visible light for communication that occupies the spectrum from approximately 380 nm to 750 nm, corresponding to a frequency spectrum of approximately 430 THz to 790 THz. The low bandwidth problem in RF communication is resolved in VLC because of the large bandwidth available in the VLC spectrum. Further, the VLC receiver only receives signals if they reside in the same room as the transmitter and receivers outside the room of the VLC source will not be able to receive the signals, contrary to an RF signal which may be received by any receiver configured to the appropriate frequency and within range of the RF transmission. Thus, VLC systems do not have certain security issues that occur in RF communication systems. Moreover, as a visible light source can be used both for illumination and communication, VLC systems save the extra power that is required in RF communication. These features of VLC (high bandwidth, no health hazard, low power consumption and non-licensed channels) have made VLC lighting systems attractive for practical use. DLC systems similarly use non-visible light, such as infrared wavelengths, for light-based communications.
Some of the applications using VLC are: Light Fidelity (Li-Fi); vehicle-to-vehicle communication; underwater communication; hospitals; information-displaying signboards; visible light ID systems; Wireless Local Area Networks (WLANs); dimming; etc. The revolution in the field of solid-state lighting has also led to the replacement of many florescent lamps by Light Emitting Diodes (LEDs), which further motivates the usage of VLC because LEDs provide, for example, relatively high intensity light sources with low power consumption.
VLC enabled LED luminaires, in addition to the infrared synchronization protocol, enabled inexpensive white LEDs to be time division multiplexed to avoid packet collisions. Luminaires use token message passing to regulate packet transmission.
VLC also enables LED light fixtures to broadcast positioning signals using rapid modulation of light in a way that does not affect their primary functionality of providing illumination. The positioning signals are decoded by, e.g., smartphone devices using their built-in front-facing camera (image) sensors and are used to compute the device's position in the venue. These positioning signals work like a beacon that emits information to the environment.
Further, distributed multi-hop VLC provides 360° coverage for directionality, and a flexible design.
However, there is a need for unique use of VLC in luminaire industry that is less expensive particularly in Internet of Things (IoT) based lighting control systems.
For a VLC to emit location information to the environment, it needs to know its own location. A specific location inside a room with no GPS access is required as the GPS cannot be used for accuracy reasons and thus a lighting device does not know its own location. Further, the gateway that uses the VLC/DLC to communicate either knows the location or needs to learn the location. The problem associated in finding the exact location of the luminaire relative to the room and to other luminaires thus do exists and is addressed by the present disclosure.
Further, once the addresses of all luminaire control devices are known along with location information, the next process conducted will be to assign them to operational groups, representing areas such as rooms and corridors. This is ordinarily achieved by manually assigning known addressed devices to a group object so that all members can be controlled by a single command/message when later configured/programmed.
As the size of a single lighting control network grows beyond that of a single zone of a floor, to the whole floor, the whole building and areas beyond; the time and labor expended on luminaire/networked device identification will likely be quite extensive. Most presently employed methods of device identification require some form of direct manual interaction and/or direct observation of the individual luminaire being identified.
With the emergence of Internet of Things (IoT) based lighting control systems, the size of a single installation when compared to existing localized networked solutions will grow in size significantly due to the absence of limitations imposed by more localized technologies. As such, in order to reduce the installation and commissioning time for a large project based on the issues outlined, the requirement for an automated method of luminaire location identification using light based communication/VLC/DLC becomes apparent.
If during the physical installation of an intelligent lighting control system, all information regarding addresses and locations has been accurately mapped and added directly to a commissioning application/tool or drawing, the issue of post-installation identification may not generally present a major problem; however from experience this is not always accurately carried out by electricians/installers and physical media such as installation drawings (with IDs attached) can be lost/damaged. Further, when changing devices, or replacing the gateway or the luminaire, the installer needs to follow a long manual procedure that is open to errors.
In view of the above, there is a need for a cost effective unique use of VLC/DLC technology for determining the exact location of the luminaire relative to the room and to other luminaires and grouping of luminaires based on VLC/DLC modulation techniques. Further, there is a need for system and method for automatic luminaire location identification using light based communication/VLC/DLC for commissioning a lighting control in very large ecosystems such as a whole building or a floor, in quick turn-around time and reducing manual efforts.